linux-stable.git/include, branch v5.0.6

mm: add support for kmem caches in DMA32 zone

2019-04-03T04:27:37+00:00

commit 6d6ea1e967a246f12cfe2f5fb743b70b2e608d4a upstream.

Patch series "iommu/io-pgtable-arm-v7s: Use DMA32 zone for page tables",
v6.

This is a followup to the discussion in [1], [2].

IOMMUs using ARMv7 short-descriptor format require page tables (level 1
and 2) to be allocated within the first 4GB of RAM, even on 64-bit
systems.

For L1 tables that are bigger than a page, we can just use
__get_free_pages with GFP_DMA32 (on arm64 systems only, arm would still
use GFP_DMA).

For L2 tables that only take 1KB, it would be a waste to allocate a full
page, so we considered 3 approaches:
 1. This series, adding support for GFP_DMA32 slab caches.
 2. genalloc, which requires pre-allocating the maximum number of L2 page
    tables (4096, so 4MB of memory).
 3. page_frag, which is not very memory-efficient as it is unable to reuse
    freed fragments until the whole page is freed. [3]

This series is the most memory-efficient approach.

stable@ note:
  We confirmed that this is a regression, and IOMMU errors happen on 4.19
  and linux-next/master on MT8173 (elm, Acer Chromebook R13). The issue
  most likely starts from commit ad67f5a6545f ("arm64: replace ZONE_DMA
  with ZONE_DMA32"), i.e. 4.15, and presumably breaks a number of Mediatek
  platforms (and maybe others?).

[1] https://lists.linuxfoundation.org/pipermail/iommu/2018-November/030876.html
[2] https://lists.linuxfoundation.org/pipermail/iommu/2018-December/031696.html
[3] https://patchwork.codeaurora.org/patch/671639/

This patch (of 3):

IOMMUs using ARMv7 short-descriptor format require page tables to be
allocated within the first 4GB of RAM, even on 64-bit systems.  On arm64,
this is done by passing GFP_DMA32 flag to memory allocation functions.

For IOMMU L2 tables that only take 1KB, it would be a waste to allocate
a full page using get_free_pages, so we considered 3 approaches:
 1. This patch, adding support for GFP_DMA32 slab caches.
 2. genalloc, which requires pre-allocating the maximum number of L2
    page tables (4096, so 4MB of memory).
 3. page_frag, which is not very memory-efficient as it is unable
    to reuse freed fragments until the whole page is freed.

This change makes it possible to create a custom cache in DMA32 zone using
kmem_cache_create, then allocate memory using kmem_cache_alloc.

We do not create a DMA32 kmalloc cache array, as there are currently no
users of kmalloc(..., GFP_DMA32).  These calls will continue to trigger a
warning, as we keep GFP_DMA32 in GFP_SLAB_BUG_MASK.

This implies that calls to kmem_cache_*alloc on a SLAB_CACHE_DMA32
kmem_cache must _not_ use GFP_DMA32 (it is anyway redundant and
unnecessary).

Link: http://lkml.kernel.org/r/20181210011504.122604-2-drinkcat@chromium.org
Signed-off-by: Nicolas Boichat 
Acked-by: Vlastimil Babka 
Acked-by: Will Deacon 
Cc: Robin Murphy 
Cc: Joerg Roedel 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Cc: Michal Hocko 
Cc: Mel Gorman 
Cc: Sasha Levin 
Cc: Huaisheng Ye 
Cc: Mike Rapoport 
Cc: Yong Wu 
Cc: Matthias Brugger 
Cc: Tomasz Figa 
Cc: Yingjoe Chen 
Cc: Christoph Hellwig 
Cc: Matthew Wilcox 
Cc: Hsin-Yi Wang 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

mm/hotplug: fix offline undo_isolate_page_range()

2019-04-03T04:27:36+00:00

commit 9b7ea46a82b31c74a37e6ff1c2a1df7d53e392ab upstream.

Commit f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded
memory to zones until online") introduced move_pfn_range_to_zone() which
calls memmap_init_zone() during onlining a memory block.
memmap_init_zone() will reset pagetype flags and makes migrate type to
be MOVABLE.

However, in __offline_pages(), it also call undo_isolate_page_range()
after offline_isolated_pages() to do the same thing.  Due to commit
2ce13640b3f4 ("mm: __first_valid_page skip over offline pages") changed
__first_valid_page() to skip offline pages, undo_isolate_page_range()
here just waste CPU cycles looping around the offlining PFN range while
doing nothing, because __first_valid_page() will return NULL as
offline_isolated_pages() has already marked all memory sections within
the pfn range as offline via offline_mem_sections().

Also, after calling the "useless" undo_isolate_page_range() here, it
reaches the point of no returning by notifying MEM_OFFLINE.  Those pages
will be marked as MIGRATE_MOVABLE again once onlining.  The only thing
left to do is to decrease the number of isolated pageblocks zone counter
which would make some paths of the page allocation slower that the above
commit introduced.

Even if alloc_contig_range() can be used to isolate 16GB-hugetlb pages
on ppc64, an "int" should still be enough to represent the number of
pageblocks there.  Fix an incorrect comment along the way.

[cai@lca.pw: v4]
  Link: http://lkml.kernel.org/r/20190314150641.59358-1-cai@lca.pw
Link: http://lkml.kernel.org/r/20190313143133.46200-1-cai@lca.pw
Fixes: 2ce13640b3f4 ("mm: __first_valid_page skip over offline pages")
Signed-off-by: Qian Cai 
Acked-by: Michal Hocko 
Reviewed-by: Oscar Salvador 
Cc: Vlastimil Babka 
Cc: 	[4.13+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

net: mii: Fix PAUSE cap advertisement from linkmode_adv_to_lcl_adv_t() helper

2019-04-03T04:27:26+00:00

[ Upstream commit 7f07e5f1f778605e98cf2156d4db1ff3a3a1a74a ]

With a recent link mode advertisement code update this helper
providing local pause capability translation used for flow
control link mode negotiation got broken.
For eth drivers using this helper, the issue is apparent only
if either PAUSE or ASYM_PAUSE is being advertised.

Fixes: 3c1bcc8614db ("net: ethernet: Convert phydev advertize and supported from u32 to link mode")
Signed-off-by: Claudiu Manoil 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: get sctphdr by offset in sctp_compute_cksum

2019-04-03T04:27:24+00:00

[ Upstream commit 273160ffc6b993c7c91627f5a84799c66dfe4dee ]

sctp_hdr(skb) only works when skb->transport_header is set properly.

But in Netfilter, skb->transport_header for ipv6 is not guaranteed
to be right value for sctphdr. It would cause to fail to check the
checksum for sctp packets.

So fix it by using offset, which is always right in all places.

v1->v2:
  - Fix the changelog.

Fixes: e6d8b64b34aa ("net: sctp: fix and consolidate SCTP checksumming code")
Reported-by: Li Shuang 
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

packets: Always register packet sk in the same order

2019-04-03T04:27:24+00:00

[ Upstream commit a4dc6a49156b1f8d6e17251ffda17c9e6a5db78a ]

When using fanouts with AF_PACKET, the demux functions such as
fanout_demux_cpu will return an index in the fanout socket array, which
corresponds to the selected socket.

The ordering of this array depends on the order the sockets were added
to a given fanout group, so for FANOUT_CPU this means sockets are bound
to cpus in the order they are configured, which is OK.

However, when stopping then restarting the interface these sockets are
bound to, the sockets are reassigned to the fanout group in the reverse
order, due to the fact that they were inserted at the head of the
interface's AF_PACKET socket list.

This means that traffic that was directed to the first socket in the
fanout group is now directed to the last one after an interface restart.

In the case of FANOUT_CPU, traffic from CPU0 will be directed to the
socket that used to receive traffic from the last CPU after an interface
restart.

This commit introduces a helper to add a socket at the tail of a list,
then uses it to register AF_PACKET sockets.

Note that this changes the order in which sockets are listed in /proc and
with sock_diag.

Fixes: dc99f600698d ("packet: Add fanout support")
Signed-off-by: Maxime Chevallier 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: fix set double-free in abort path

2019-04-03T04:27:22+00:00

[ Upstream commit 40ba1d9b4d19796afc9b7ece872f5f3e8f5e2c13 ]

The abort path can cause a double-free of an anonymous set.
Added-and-to-be-aborted rule looks like this:

udp dport { 137, 138 } drop

The to-be-aborted transaction list looks like this:

newset
newsetelem
newsetelem
rule

This gets walked in reverse order, so first pass disables the rule, the
set elements, then the set.

After synchronize_rcu(), we then destroy those in same order: rule, set
element, set element, newset.

Problem is that the anonymous set has already been bound to the rule, so
the rule (lookup expression destructor) already frees the set, when then
cause use-after-free when trying to delete the elements from this set,
then try to free the set again when handling the newset expression.

Rule releases the bound set in first place from the abort path, this
causes the use-after-free on set element removal when undoing the new
element transactions. To handle this, skip new element transaction if
set is bound from the abort path.

This is still causes the use-after-free on set element removal.  To
handle this, remove transaction from the list when the set is already
bound.

Joint work with Florian Westphal.

Fixes: f6ac85858976 ("netfilter: nf_tables: unbind set in rule from commit path")
Bugzilla: https://bugzilla.netfilter.org/show_bug.cgi?id=1325
Acked-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

aio: simplify - and fix - fget/fput for io_submit()

2019-03-27T05:17:59+00:00

commit 84c4e1f89fefe70554da0ab33be72c9be7994379 upstream.

Al Viro root-caused a race where the IOCB_CMD_POLL handling of
fget/fput() could cause us to access the file pointer after it had
already been freed:

 "In more details - normally IOCB_CMD_POLL handling looks so:

   1) io_submit(2) allocates aio_kiocb instance and passes it to
      aio_poll()

   2) aio_poll() resolves the descriptor to struct file by req->file =
      fget(iocb->aio_fildes)

   3) aio_poll() sets ->woken to false and raises ->ki_refcnt of that
      aio_kiocb to 2 (bumps by 1, that is).

   4) aio_poll() calls vfs_poll(). After sanity checks (basically,
      "poll_wait() had been called and only once") it locks the queue.
      That's what the extra reference to iocb had been for - we know we
      can safely access it.

   5) With queue locked, we check if ->woken has already been set to
      true (by aio_poll_wake()) and, if it had been, we unlock the
      queue, drop a reference to aio_kiocb and bugger off - at that
      point it's a responsibility to aio_poll_wake() and the stuff
      called/scheduled by it. That code will drop the reference to file
      in req->file, along with the other reference to our aio_kiocb.

   6) otherwise, we see whether we need to wait. If we do, we unlock the
      queue, drop one reference to aio_kiocb and go away - eventual
      wakeup (or cancel) will deal with the reference to file and with
      the other reference to aio_kiocb

   7) otherwise we remove ourselves from waitqueue (still under the
      queue lock), so that wakeup won't get us. No async activity will
      be happening, so we can safely drop req->file and iocb ourselves.

  If wakeup happens while we are in vfs_poll(), we are fine - aio_kiocb
  won't get freed under us, so we can do all the checks and locking
  safely. And we don't touch ->file if we detect that case.

  However, vfs_poll() most certainly *does* touch the file it had been
  given. So wakeup coming while we are still in ->poll() might end up
  doing fput() on that file. That case is not too rare, and usually we
  are saved by the still present reference from descriptor table - that
  fput() is not the final one.

  But if another thread closes that descriptor right after our fget()
  and wakeup does happen before ->poll() returns, we are in trouble -
  final fput() done while we are in the middle of a method:

Al also wrote a patch to take an extra reference to the file descriptor
to fix this, but I instead suggested we just streamline the whole file
pointer handling by submit_io() so that the generic aio submission code
simply keeps the file pointer around until the aio has completed.

Fixes: bfe4037e722e ("aio: implement IOCB_CMD_POLL")
Acked-by: Al Viro 
Reported-by: syzbot+503d4cc169fcec1cb18c@syzkaller.appspotmail.com
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

libceph: wait for latest osdmap in ceph_monc_blacklist_add()

2019-03-27T05:17:52+00:00

commit bb229bbb3bf63d23128e851a1f3b85c083178fa1 upstream.

Because map updates are distributed lazily, an OSD may not know about
the new blacklist for quite some time after "osd blacklist add" command
is completed.  This makes it possible for a blacklisted but still alive
client to overwrite a post-blacklist update, resulting in data
corruption.

Waiting for latest osdmap in ceph_monc_blacklist_add() and thus using
the post-blacklist epoch for all post-blacklist requests ensures that
all such requests "wait" for the blacklist to come into force on their
respective OSDs.

Cc: stable@vger.kernel.org
Fixes: 6305a3b41515 ("libceph: support for blacklisting clients")
Signed-off-by: Ilya Dryomov 
Reviewed-by: Jason Dillaman 
Signed-off-by: Greg Kroah-Hartman

KVM: Call kvm_arch_memslots_updated() before updating memslots

2019-03-23T19:11:40+00:00

commit 152482580a1b0accb60676063a1ac57b2d12daf6 upstream.

kvm_arch_memslots_updated() is at this point in time an x86-specific
hook for handling MMIO generation wraparound.  x86 stashes 19 bits of
the memslots generation number in its MMIO sptes in order to avoid
full page fault walks for repeat faults on emulated MMIO addresses.
Because only 19 bits are used, wrapping the MMIO generation number is
possible, if unlikely.  kvm_arch_memslots_updated() alerts x86 that
the generation has changed so that it can invalidate all MMIO sptes in
case the effective MMIO generation has wrapped so as to avoid using a
stale spte, e.g. a (very) old spte that was created with generation==0.

Given that the purpose of kvm_arch_memslots_updated() is to prevent
consuming stale entries, it needs to be called before the new generation
is propagated to memslots.  Invalidating the MMIO sptes after updating
memslots means that there is a window where a vCPU could dereference
the new memslots generation, e.g. 0, and incorrectly reuse an old MMIO
spte that was created with (pre-wrap) generation==0.

Fixes: e59dbe09f8e6 ("KVM: Introduce kvm_arch_memslots_updated()")
Cc: 
Signed-off-by: Sean Christopherson 
Signed-off-by: Paolo Bonzini 
Signed-off-by: Greg Kroah-Hartman

x86/unwind/orc: Fix ORC unwind table alignment

2019-03-23T19:11:37+00:00

commit f76a16adc485699f95bb71fce114f97c832fe664 upstream.

The .orc_unwind section is a packed array of 6-byte structs.  It's
currently aligned to 6 bytes, which is causing warnings in the LLD
linker.

Six isn't a power of two, so it's not a valid alignment value.  The
actual alignment doesn't matter much because it's an array of packed
structs.  An alignment of two is sufficient.  In reality it always gets
aligned to four bytes because it comes immediately after the
4-byte-aligned .orc_unwind_ip section.

Fixes: ee9f8fce9964 ("x86/unwind: Add the ORC unwinder")
Reported-by: Nick Desaulniers 
Reported-by: Dmitry Golovin 
Reported-by: Sedat Dilek 
Signed-off-by: Josh Poimboeuf 
Signed-off-by: Thomas Gleixner 
Tested-by: Sedat Dilek 
Cc: Peter Zijlstra 
Cc: stable@vger.kernel.org
Link: https://github.com/ClangBuiltLinux/linux/issues/218
Link: https://lkml.kernel.org/r/d55027ee95fe73e952dcd8be90aebd31b0095c45.1551892041.git.jpoimboe@redhat.com
Signed-off-by: Greg Kroah-Hartman